RemiD,Like Claude posted, if you post the BHV file and parameters, I will take a look. Often, these issue happen because so many different BVH generators write slightly differing formats that the parser does not anticipate or the file is simply malformed.

I have managed to import this bhv animation with Ultimate unwrap 3d and with Fragmotion and with Blender and the tpose skeleton seems ok but the animated skeleton seems weirdly scaled stretched... (but the animation seems correct) I am trying to determine if this weird scaling stretching comes from an error in the exporter (of a software which exports motion captured animations in bhv biovision) or from the importer.

Just to let you know that i have solved the weird scaling stretching of the skeleton while it is animating (you have to remove all translation/position keys of all joints/bones except those of the root joint/bone)

However i still have the error when trying to convert the bhv file to an an8 file using BVH2Anim8or.

(i don't really need to use anim8or but it would be good to fix this bug anyway for the others users, as you want...)

I haven't had such problems. Your converter is simply amazing. I used it a lot in the past, and I would even send you a beer on Paypal. I'm only referring to the "jiggle" I had in some movements a while back, which I had to manually correct. I remember that had to do with the IK system anim8or had back then. I'll get my new laptop in a couple of days and make some new tests.